The inventions relates to non-ferrous metallurgy, and more particularly, to production of modern titanium alloys preferably used for manufacturing of large-sized forgings, stampings, fasteners and other parts for aeronautical engineering.
Titanium-based alloy of the following composition, % by mass, is known:
(RF Patent # 2122040, C22C 14/00, 1998) as the prototype.
The said alloy possesses a good combination of high strength and plasticity of large-sized parts up to 150-200 mm thick, water or air hardened. The alloy is easily hot deformed and is welded by argon-arc and electron-bean welding.
The disadvantage of the alloy is an insufficient level of strength of massive large-sized parts more than 150-200 mm thick, air hardened.
The method of heat treatment of large-sized semifinished items made of two-phase titanium alloys comprising pre-heating up to the temperature 7-50xc2x0 C. higher than the polymorphic transformation temperature, holding for 0.15-3 hours, cooling to the two-phase region temperature, 20-80xc2x0 C. lower than the polymorphic transformation temperature, holding for 0.15-3 hours, hardening and aging is known (USSR Inventor""s Certificate # 912771. C22F, Jan. 18, 1982) as the prototype.
The disadvantage of the method is an insufficient level of strength of massive large-sized parts more than 150-200 mm thick.